Radio receivers that make use of antenna selection diversity are known in the art. In general, such a receiver makes use of a default antenna, and only makes use of the alternate antenna when the signal being received by the default antenna diminishes below an acceptable threshold (the threshold may either be a preselected constant or a value that fluctuates somewhat and represents, for example, an average value of the default antenna received signal). The criteria for measuring antenna performance may be, for example, a received signal strength indicator (RSSI).
Time division multiplexed (TDM) RF communications systems are also known in the art. Such systems divide information to be broadcast into packets, which packets are then broadcast in predetermined time slots. A typical TDM system establishes a short time frame (for example, a few milliseconds) made up of two or more time slots, wherein the basic time frame format repeats continuously. A typical receiver will monitor, decode, and process further as appropriate information contained in time slots of interest, and receive but ignore information contained in other time slots. (Additional information regarding TDM RF systems can be found in U.S. Ser. No. 843,882 and Ser. No. 843,961, both as filed on Mar. 25, 1986 and both incorporated herein by this reference.)
A need exists to accommodate antenna selection diversity in a TDM RF receiver.